// Copyright (C) 2026 Whiterun LLC,
// This software is licensed under the GNU Lesser General Public License (LGPL), version 3.0 or later.
// A copy of the license can be found in the LICENSE file or at https://www.gnu.org/licenses/lgpl-3.0.html

import { describe, it, expect } from "vitest";
import {
  encodeKeyExchangeURI,
  decodeKeyExchangeURI,
  generateKeyExchangeCredentials,
  DEFAULT_RELAY_URLS,
  DEFAULT_RELAY_HOSTNAME,
} from "./key-exchange.js";

describe("key-exchange", () => {
  describe("generateKeyExchangeCredentials", () => {
    it("should generate valid credentials", () => {
      const credentials = generateKeyExchangeCredentials();

      expect(credentials.privateKey).toHaveLength(64); // 32 bytes in hex
      expect(credentials.publicKey).toHaveLength(64); // 32 bytes in hex
      expect(credentials.secret).toHaveLength(16); // 8 bytes in hex

      // Verify all are valid hex strings
      expect(/^[0-9a-f]+$/.test(credentials.privateKey)).toBe(true);
      expect(/^[0-9a-f]+$/.test(credentials.publicKey)).toBe(true);
      expect(/^[0-9a-f]+$/.test(credentials.secret)).toBe(true);
    });

    it("should generate different credentials on each call", () => {
      const cred1 = generateKeyExchangeCredentials();
      const cred2 = generateKeyExchangeCredentials();

      expect(cred1.privateKey).not.toBe(cred2.privateKey);
      expect(cred1.publicKey).not.toBe(cred2.publicKey);
      expect(cred1.secret).not.toBe(cred2.secret);
    });
  });

  describe("encodeKeyExchangeURI", () => {
    it("should encode valid public key and secret to URI", () => {
      const publicKey = "a".repeat(64); // 32 bytes in hex
      const secret = "b".repeat(16); // 8 bytes in hex

      const { uri } = encodeKeyExchangeURI(publicKey, secret);

      // With defaults, should use minimal URI format
      expect(uri).toMatch(
        /^wiz:\/\/\?p=[qpzry9x8gf2tvdw0s3jn54khce6mua7l]+&s=[qpzry9x8gf2tvdw0s3jn54khce6mua7l]+$/,
      );
      expect(uri.startsWith("wiz://?")).toBe(true);
      expect(uri.includes("?p=")).toBe(true);
      expect(uri.includes("&s=")).toBe(true);
    });

    it("should always produce lowercase bech32 encoding", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);

      const { uri } = encodeKeyExchangeURI(publicKey, secret);

      // Extract the bech32 parts (minimal URI format)
      const parts = uri.match(/^wiz:\/\/\?p=([^&]+)&s=(.+)$/);
      expect(parts).not.toBeNull();
      if (parts) {
        expect(parts[1]).toBe(parts[1].toLowerCase());
        expect(parts[2]).toBe(parts[2].toLowerCase());
      }
    });

    it("should throw error for invalid public key length", () => {
      // Use a hex string that decodes to wrong length (odd length hex = invalid)
      const invalidPublicKey = "a".repeat(62); // 31 bytes when decoded
      const secret = "b".repeat(16);

      expect(() => encodeKeyExchangeURI(invalidPublicKey, secret)).toThrow(
        "Invalid public key length",
      );
    });

    it("should throw error for invalid secret length", () => {
      const publicKey = "a".repeat(64);
      // Use a hex string that decodes to wrong length (odd length hex = invalid)
      const invalidSecret = "b".repeat(14); // 7 bytes when decoded

      expect(() => encodeKeyExchangeURI(publicKey, invalidSecret)).toThrow(
        "Invalid secret length",
      );
    });

    it("should handle invalid hex gracefully", () => {
      // hexToBin from libauth might be lenient with invalid hex
      // This test verifies the function doesn't crash, but the actual behavior
      // depends on libauth's hexToBin implementation
      const invalidPublicKey = "g".repeat(64); // 'g' is not valid hex
      const secret = "b".repeat(16);

      // The function should either throw or produce a result
      // If it doesn't throw, it means libauth's hexToBin is lenient
      // In that case, it will likely fail at length validation
      try {
        encodeKeyExchangeURI(invalidPublicKey, secret);
        // If it doesn't throw, that's also acceptable behavior
      } catch (error) {
        // If it throws, that's expected
        expect(error).toBeDefined();
      }
    });
  });

  describe("encodeKeyExchangeURI — qrUri", () => {
    it("qrUri is fully uppercase", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { qrUri } = encodeKeyExchangeURI(publicKey, secret);
      expect(qrUri).toBe(qrUri.toUpperCase());
    });

    it("qrUri contains no ?, =, or &", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { qrUri } = encodeKeyExchangeURI(publicKey, secret);
      expect(qrUri).not.toContain("?");
      expect(qrUri).not.toContain("=");
      expect(qrUri).not.toContain("&");
    });

    it("qrUri passes QR alphanumeric charset regex", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { qrUri } = encodeKeyExchangeURI(publicKey, secret);
      expect(/^[A-Z0-9 $%*+\-./:]+$/.test(qrUri)).toBe(true);
    });

    it("qrUri contains %3F, %3D, %26 for default relay", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { qrUri } = encodeKeyExchangeURI(publicKey, secret);
      expect(qrUri).toContain("%3F");
      expect(qrUri).toContain("%3D");
      expect(qrUri).toContain("%26");
    });

    it("custom relay encodes all separators", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { qrUri } = encodeKeyExchangeURI(publicKey, secret, {
        hostname: "example.com",
        port: 8080,
        protocol: "ws",
      });
      expect(qrUri).not.toContain("?");
      expect(qrUri).not.toContain("=");
      expect(qrUri).not.toContain("&");
      expect(/^[A-Z0-9 $%*+\-./:]+$/.test(qrUri)).toBe(true);
    });
  });

  describe("decodeKeyExchangeURI", () => {
    it("should decode valid URI to public key and secret", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { uri } = encodeKeyExchangeURI(publicKey, secret);

      const decoded = decodeKeyExchangeURI(uri);

      expect(decoded.publicKey).toBe(publicKey);
      expect(decoded.secret).toBe(secret);
    });

    it("should handle case-insensitive URIs", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { uri } = encodeKeyExchangeURI(publicKey, secret);

      // Test uppercase URI (but keep scheme lowercase as URL parsing requires it)
      const upperUri = uri.replace(/wiz:\/\/([^?]+)/, (match, host) => {
        return `wiz://${host.toUpperCase()}`;
      });
      const decoded = decodeKeyExchangeURI(upperUri);

      expect(decoded.publicKey).toBe(publicKey);
      expect(decoded.secret).toBe(secret);
    });

    it("should handle mixed case URIs", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { uri } = encodeKeyExchangeURI(publicKey, secret);

      // Mix case
      const mixedUri = uri.replace(/r/i, "R").replace(/c/i, "C");
      const decoded = decodeKeyExchangeURI(mixedUri);

      expect(decoded.publicKey).toBe(publicKey);
      expect(decoded.secret).toBe(secret);
    });

    it("should throw error for invalid URI format", () => {
      const invalidUri = "invalid://uri";

      expect(() => decodeKeyExchangeURI(invalidUri)).toThrow();
    });

    it("should throw error for wrong scheme", () => {
      const invalidUri = "wrong://relay.riften.net?p=abc&s=def";

      expect(() => decodeKeyExchangeURI(invalidUri)).toThrow(
        "Invalid URI scheme",
      );
    });

    it("should handle URIs with custom hostname and port", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);

      const { uri } = encodeKeyExchangeURI(publicKey, secret, {
        hostname: "example.com",
        port: 8080,
        protocol: "ws",
      });

      expect(uri).toMatch(/^wiz:\/\/example\.com:8080\?p=/);
      const decoded = decodeKeyExchangeURI(uri);
      expect(decoded.hostname).toBe("example.com");
      expect(decoded.port).toBe(8080);
      expect(decoded.protocol).toBe("ws");
    });

    it("should throw error for missing parameters", () => {
      const invalidUri = "wiz://relay.riften.net?p=abc";

      expect(() => decodeKeyExchangeURI(invalidUri)).toThrow(
        "Invalid URI format",
      );
    });

    it("should throw error for invalid bech32 encoding", () => {
      // Use invalid bech32 characters (bech32 only uses: qpzry9x8gf2tvdw0s3jn54khce6mua7l)
      // This will fail at bech32 decoding
      const invalidUri = "wiz://relay.riften.net?p=invalid&s=chars";

      expect(() => decodeKeyExchangeURI(invalidUri)).toThrow(
        "Invalid bech32 encoding",
      );
    });

    it("should throw error for wrong public key length after decoding", () => {
      // Create a bech32 string that decodes to wrong length
      const shortBech32 = "q";
      const { uri: validSecret } = encodeKeyExchangeURI(
        "a".repeat(64),
        "b".repeat(16),
      );
      const secretPart = validSecret.match(/&s=(.+)$/)?.[1] || "";
      const invalidUri = `wiz://relay.riften.net?p=${shortBech32}&s=${secretPart}`;

      expect(() => decodeKeyExchangeURI(invalidUri)).toThrow();
    });

    it("should throw error for wrong secret length after decoding", () => {
      const { uri: validPublicKey } = encodeKeyExchangeURI(
        "a".repeat(64),
        "b".repeat(16),
      );
      const publicKeyPart = validPublicKey.match(/p=([^&]+)/)?.[1] || "";
      const shortBech32 = "q";
      const invalidUri = `wiz://relay.riften.net?p=${publicKeyPart}&s=${shortBech32}`;

      expect(() => decodeKeyExchangeURI(invalidUri)).toThrow();
    });
  });

  describe("decodeKeyExchangeURI — QR format", () => {
    it("decodes qrUri to same values as standard uri", () => {
      const publicKey = "0123456789abcdef".repeat(4);
      const secret = "fedcba9876543210";
      const { uri, qrUri } = encodeKeyExchangeURI(publicKey, secret);

      const fromUri = decodeKeyExchangeURI(uri);
      const fromQr = decodeKeyExchangeURI(qrUri);

      expect(fromQr.publicKey).toBe(fromUri.publicKey);
      expect(fromQr.secret).toBe(fromUri.secret);
      expect(fromQr.hostname).toBe(fromUri.hostname);
      expect(fromQr.port).toBe(fromUri.port);
      expect(fromQr.protocol).toBe(fromUri.protocol);
    });

    it("accepts lowercase version of qrUri", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { uri, qrUri } = encodeKeyExchangeURI(publicKey, secret);

      const fromUri = decodeKeyExchangeURI(uri);
      const fromLowerQr = decodeKeyExchangeURI(qrUri.toLowerCase());

      expect(fromLowerQr.publicKey).toBe(fromUri.publicKey);
      expect(fromLowerQr.secret).toBe(fromUri.secret);
    });

    it("round-trip: encodeKeyExchangeURI → qrUri → decodeKeyExchangeURI", () => {
      const credentials = generateKeyExchangeCredentials();
      const { qrUri } = encodeKeyExchangeURI(
        credentials.publicKey,
        credentials.secret,
      );
      const decoded = decodeKeyExchangeURI(qrUri);

      expect(decoded.publicKey).toBe(credentials.publicKey);
      expect(decoded.secret).toBe(credentials.secret);
    });

    it("round-trip with custom relay via qrUri", () => {
      const publicKey = "a".repeat(64);
      const secret = "b".repeat(16);
      const { qrUri } = encodeKeyExchangeURI(publicKey, secret, {
        hostname: "example.com",
        port: 8080,
        protocol: "ws",
      });
      const decoded = decodeKeyExchangeURI(qrUri);

      expect(decoded.publicKey).toBe(publicKey);
      expect(decoded.secret).toBe(secret);
      expect(decoded.hostname).toBe("example.com");
      expect(decoded.port).toBe(8080);
      expect(decoded.protocol).toBe("ws");
    });
  });

  describe("round-trip encoding/decoding", () => {
    it("should round-trip encode and decode correctly", () => {
      const publicKey = "0123456789abcdef".repeat(4); // 32 bytes
      const secret = "fedcba9876543210"; // 8 bytes

      const { uri } = encodeKeyExchangeURI(publicKey, secret);
      const decoded = decodeKeyExchangeURI(uri);

      expect(decoded.publicKey).toBe(publicKey);
      expect(decoded.secret).toBe(secret);
    });

    it("should round-trip with generated credentials", () => {
      const credentials = generateKeyExchangeCredentials();

      const { uri } = encodeKeyExchangeURI(
        credentials.publicKey,
        credentials.secret,
      );
      const decoded = decodeKeyExchangeURI(uri);

      expect(decoded.publicKey).toBe(credentials.publicKey);
      expect(decoded.secret).toBe(credentials.secret);
    });

    it("should round-trip with random hex values", () => {
      const randomHex = (length: number) => {
        const chars = "0123456789abcdef";
        let result = "";
        for (let i = 0; i < length; i++) {
          result += chars[Math.floor(Math.random() * chars.length)];
        }
        return result;
      };

      const publicKey = randomHex(64);
      const secret = randomHex(16);

      const { uri } = encodeKeyExchangeURI(publicKey, secret);
      const decoded = decodeKeyExchangeURI(uri);

      expect(decoded.publicKey).toBe(publicKey);
      expect(decoded.secret).toBe(secret);
    });
  });

  describe("DEFAULT_RELAY_URLS", () => {
    it("has relay.riften.net as primary (first entry)", () => {
      expect(DEFAULT_RELAY_URLS[0]).toBe("wss://relay.riften.net:443");
    });

    it("contains relay.cauldron.quest as secondary", () => {
      expect(DEFAULT_RELAY_URLS).toContain("wss://relay.cauldron.quest:443");
    });

    it("primary URL matches DEFAULT_RELAY_HOSTNAME", () => {
      expect(DEFAULT_RELAY_URLS[0]).toContain(DEFAULT_RELAY_HOSTNAME);
    });
  });
});